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The Properties of Nanosilver – Doped Nanohydroxyapatite Coating On the Ti13zr13Nb Alloy

Bartmanski M.

Advances in Materials Science

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2017

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Vol. 17, nr 2(52)

18--28

EN

The aim of this research was to study the properties of nanohydroxyapatite (nanoHAp) and nanohydroxyapatite, doped with nanosilver (nanoHAp/nanoAg), coatings obtained by an electrophoretic deposition process. The suspensions was prepared by dispersing 0.1 g of HAp nanopowder for nanoHAp coatings and 0.1 g of nanoHAp and 0.025 g nanoAg for nanoHAp/nanoAg coatings. The deposition was carried out for 1 min at 50 V voltage followed by drying at room temperature for 24 h and heating at 800°C for 1 h in vacuum. The thickness of the nanoHAp and nanoHAp/nanoAg coatings was found as of about 5 μm. The corrosion behavior tests made by potentiodynamic methods brought out slightly higher values of corrosion current for nanoHAp coatings and nanoHAp/nanoAg coatings as compared to the reference Ti13Zr13Nb specimen. The nanohardness of the nanoHAp coatings achieved 0.020 ± 0.004 GPa and of the nanoHAp/nanoAg coatings 0.026 ± 0.012 GPa. Nanoscratch test of the nanoHAp and nanoHAp/nanoAg coatings revealed an increased Critical Friction (mN) in the presence of nanosilver particles. The wettability angles decreased for nanoHAp/nanoAg coatings comparing to pure nanoHAp coatings on titanium alloy.

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The determinants of morphology and properties of the nanohydroxyapatite coating deposited on the Ti13Zr13Nb alloy by electrophoretic technique

Bartmański M., Berk A., Wójcik A.

Advances in Materials Science

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2016

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Vol. 16, nr 3(49)

56--66

EN

The titanium and its alloys belong at present to the most preferred and commonly applied biomaterials for load-bearing implants. The surfaces of biomaterials are subjected to modification, including the hydroxyapatite coatings deposited in order to ensure corrosion resistance and better joining between an implant and a bone through the possibility of ingrowth bone into the coating. In this paper, the morphology and properties of the nanohydroxyapatite coating deposited on the Ti13Zr13Nb flat surfaces using electrophoretic method are presented. Electrophoretic deposition at two different current values and two electrolytes (first – ethanol with nanoHAp, second – methanol with nanoHAp) was applied. The scanning electron microscopy examinations and wettability angle measurements showed an increase in the coating thickness, the surface coverage and decrease in biocompatibility with increasing voltage. The surface condition and biocompatibility of coatings were better when using methanol/nanoHAp solution as compared to the ethanol/nanoHAp one.

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Electrophoretic deposition of biphasic calcium phosphates on NiTi shape memory alloy

Dudek K., Goryczka T.

Composites Theory and Practice

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2015

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R. 15, nr 4

192--195

EN

The application of NiTi shape memory alloys as long-term implants is dependent on ensuring better biocompatibility of the alloy, which is achieved by modification of the surface by protective coatings or layers. In the present work, the surface of the NiTi alloy was covered by biocompatible composite coatings. First, a thin rutile layer was formed by autoclaving. Passivation was carried out at 134°C for 30min which resulted in forming an amorphous TiO2 thin film. Next, a biphasic calcium phosphate (BCP) layer was deposited using electrophoresis (EPD). The BCP layer was composed of hydroxyapatite (HAP) and β-tricalcium phosphate (β-TCP). The deposition voltage ranged from 40 to 80 V at a constant time of 60 s. The deposited samples were vacuum-sintered at 800°C for 2 h. Observations of the surface revealed that the obtained coatings are crack-free. Measurements done with X-ray diffraction confirmed that the top layer consisted of β-TCP and HAP.

PL

Zastosowanie stopów NiTi w medycynie na długoterminowe implanty uwarunkowane jest zapewnieniem lepszej biokompatybilności, co uzyskuje się poprzez modyfikację powierzchni wyjściowej stopów odpowiednimi biozgodnymi warstwami lub powłokami ochronnymi. W prezentowanej pracy powierzchnia stopu NiTi została zmodyfikowana poprzez wytworzenie warstwy kompozytowej składającej się z rutylu (TiO2) oraz dwufazowej ceramiki opartej o fosforany wapnia (BCP), złożonej z hydroksyapatytu (HAP) oraz ceramiki whitlockitowej (β-TCP). Warstwa rutylu została wytworzona poprzez pasywację w autoklawie parowym w warunkach stosowanych do sterylizacji narzędzi chirurgicznych (134°C, 30 min). Następnie na spasywowanej powierzchni została wytworzona metodą elektroforezy powłoka składająca się z dwufazowej ceramiki CaPs. Warstwy nałożono, stosując napięcie z zakresu 40÷80 V przy stałym czasie depozycji wynoszącym 60 s. Naniesione warstwy spiekano w piecu próżniowym w temperaturze 800°C przez 2 h. Obserwacje powierzchni przy użyciu skaningowego mikroskopu elektronowego nie wykazały pęknięć na powierzchni warstw. Badania rentgenowskie potwierdziły kompozytowy skład warstwy wierzchniej.